// ------------------------------------------------------------------------------
// 
// Copyright (c) 2006-2008 Swampware, Inc.
// 
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
// 
// ------------------------------------------------------------------------------
using System;

namespace Water.Reflection.Commands
{
	/// <summary>
	/// Summary description for IsCommand.
	/// </summary>
	public class IsCommand : Water.Commands.Command
	{

		public IsCommand()
		{
		}

		public override string Name
		{
			get { return "is"; }
		}

		public override object Evaluate(Water.List expressions, Water.Environment environment, Water.Evaluator evaluator)
		{
			if(expressions.Count != 2)
			{
				throw new Water.Commands.InvalidArgumentsException(this.Name, expressions);
			}



			object value = evaluator.Evaluate(expressions[0], environment);

			if(!(expressions[1] is Identifier))
			{
				throw new Water.Commands.InvalidArgumentsException(this.Name, expressions);
			}
			string name = ((Identifier)expressions[1]).Value;



			return IsA(name, value.GetType());
		}

		private bool IsA(string name, System.Type type)
		{
			if(type.FullName.Equals(name) || type.Name.Equals(name))
			{
				return true;
			}

			System.Type[] interfaces = type.GetInterfaces();
			foreach(System.Type iface in interfaces)
			{
				if(IsA(name, iface))
				{
					return true;
				}
			}

			if(type.BaseType != null)
			{
				return IsA(name, type.BaseType);
			}

			return false;
		}

	}
}
